Process for polymerizing α-olefins

ABSTRACT

A process for polymerizing an α-olefin comprising contacting the olefin in liquid phase at a temperature of about 120° to 320° C. with a catalyst comprising a component (A) and an organometal component (B), the component (A) being produced by reacting a hydrocarbon-soluble organomagnesium component (i) of the formula, 
     
         M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 
    
      D t   
     α, p, q, r, s and t each independently is O or a number greater than 0, 
     p+q+r+s=mα+2 
     O≦(r+s)/(α+1)&lt;2, 
     m is the valence of M, M is a metal of the 1st to 3rd groups of the Periodic Table, 
     R 1  is a hydrocarbon group having 1 to 20 carbon atoms, R 2  is a secondary or tertiary alkyl group having 3 to 20 carbon atoms, 
     X 1  and X 2  each independently is a hydrogen atom or an organic electronegative group containing O, N or S, 
     D is an electron donor, 
     with a compound (ii) of the formula, 
     
         R.sub.a.sup.3 C Y.sub.4-a 
    
     wherein 
     R 3  is a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, 
     Y is a halogen atom, 
     a is 0 or 1, 
     and contacting the product of (i)+(ii) with (iii) a compound of titanium and/or a compound of vanadium at a concentration of titanium plus vanadium of at most about 2 mols per liter of the inert reaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 to about 500.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process for polymerizing an α-olefin inliquid phase using a novel catalyst.

2. Description of the Prior Art

It is known that solution polymerization is suitable for the productionof polyethylene and its advantages are as follows;

(1) The polymerization of ethylene is an exothermic reaction and removalof heat is a big problem from the viewpoint of a process. Since theefficiency of removing heat increases with greater differences betweenthe inner temperature of a reactor and that of a cooling jacket,solution polymerization in which a high polymerization temperature isemployed is advantageous from this point.

(2) The degree of polymerization of ethylene, i.e. the molecular weightof polyethylene can be controlled comparatively accurately by varyingthe polymerization temperature and furthermore, the control of themolecular weight of polyethylene can be done by using a small amount ofhydrogen.

3) Since the molecular weight of polyethylene is correlated with theviscosity of the reaction solution, it can be estimated by measurementof the viscosity of the reaction solution in the reactor and the controlof the molecular weight of polyethylene can be quickly done accordingly.

(4) Polethylene is used or sold usually in the form of pellets. Thepolyethylene obtained by suspension polymerization and gas phasepolymerization is powdery and it is necessary to melt-mold the powderypolyethylene into pellets by an extruder. On the other hand, accordingto solution polymerization it is possible to remove the polymerizationsolvent by evaporation with the use of the heat of polymerization and tointroduce the polyethylene in its melt form into an extruder. As aresult, excess step and heat for melting the polyethylene can beomitted. In order to make the most of this advantage, it is preferredthat the polymerization temperature is high.

The disadvantage of solution polymerization is an increase in thesolution viscosity due to the increase in the solution concentration orthe molecular weight of polyethylene, which renders commercial scaleproduction of polyethylene difficult. In order to avoid thisdisadvantage, it is necessary that the polymerization temperature israised and simultaneously the solution viscosity is reduced. However,with increased polymerization temperatures the catalyst efficiency isdecreased and a large amount of catalyst residue remains in the formedpolyethylene and causes discoloration of the polyethylene anddeterioration of molded articles obtained therefrom. Further, removal ofthe catalyst residue is difficult. Thus, there are required catalystshaving a high catalyst efficiency at high temperatures which enablecomplete omission of the catalyst removal step due to the small amountof the catalyst residue present in the formed polyethylene.

There are known many Ziegler type catalysts having a high catalystefficiency for suspension polymerization (see, e.g. U.S. Pat. Nos.4,115,319, 4,159,965 and 4,163,831). However, the catalyst efficiency ofthese catalysts is, in general, decreased with increased polymerizationtemperatures, and especially at temperatures higher than about 150° C.,the decrease in the catalyst efficiency is remarkable. Thus theperformances of such catalysts are not enough to omit the removal stepof catalyst residue when employed in solution polymerization.

There are also known catalysts for solution polymerization of an olefinwhich comprise an organomagnesium complex, an aluminum halide, hydrogenchloride, a halogenated secondary or tertiary alkyl or halogenatedsilicon compound and a titanium compound (see, e.g. U.S. Pat. Nos.4,159,965 and 4,172,050 and U.K. Pat. Nos. 1,251,177 and 1,235,062).These catalysts have a higher catalyst efficiency than the conventionalcatalysts but their catalyst efficiency at high temperatures is stillinsufficient.

As a result of the study on the catalyst system for solutionpolymerization it has been discovered that by using, as a catalyst, acomponent having been obtained by reacting a specific organomagnesiumcompound with a halogenated compound and contacting the obtained productwith a titanium compound and/or a vanadium compound, in combination withan organometal component, there can be obtained catalysts having a veryhigh catalyst efficiency without any decrease at least at 150° C.,especially at least at 180° C., and an excellent storage stabilitysuitable for the polymerization of an olefin.

SUMMARY OF THE INVENTION

According to this invention there is provided a process for polymerizingan α-olefin comprising contacting the olefin in liquid phase at atemperature of about 120° to about 320° C. with a catalyst comprising acomponent (A) and an organometal component (B), the component (A) beingproduced by reacting a hydrocarbon-soluble organomagnesium component (i)of the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein

α, p, q, r, s and t each independently is 0 or a number greater than 0,

p+q+r+s=mα+2,

0≦(r+s)/(α+1)<2,

m is the valence of M,

M is a metal of the 1st to 3rd groups of the Periodic Table,

R¹ is a hydrocarbon group having 1 to 20 carbon atoms,

R² is a secondary or tertiary alkyl group having 3 to 20 carbon atoms,

X¹ and X² each independently is a hydrogen atom or an organicelectronegative group containing O, N or S,

D is an electron donor,

with a compound (ii) of the formula,

    R.sub.a.sup.3 CY.sub.4-a

wherein

R³ is a hydrogen atom or hydrocarbon group having 1 to 10 carbon atoms,

Y is a halogen atom,

a is 0 or 1,

and contacting the product of (i)+(ii) with (iii) a compound of titaniumand/or a compound of vanadium at a concentration of titanium plusvanadium of at most about 2 mols per liter of the inert reactionsolvent, the atomic ratio of Mg/Ti+V) in (A) being about 3 to about 500.

One of the characteristic features of this invention is a high catalystefficiency which reaches at least 500 Kg/g(Ti+V) as will be illustratedby the Examples. ACcordingly, the step re removing catalyst residue canbe omitted.

Another characteristic feature of this invention is that the catalyst ofthis invention is stable at high temperatures and the catalystefficiency reaches 500 Kg/g(Ti+V) at a temperature of 180° C. or higherthan 180° C.

Still another characteristic feature of this invention is that there canbe obtained polymers having a narrow molecular weight distribution, ahigh molecular weight and a high rigidity suitable for injectionmolding.

A further characteristic feature of this invention is that there can bealso obtained polymers having a broad molecular weight distributionsuitable for extrusion molding by multistage polymerization having aplurality of polymerization zones where the polymerization conditionssuch as the temperature and the concentration of hydrogen as thetemperature and the concentration of hydrogen are varied.

DETAILED DESCRIPTION OF THE INVENTION

The organomagnesium component (i) which can be used in preparing thecatalyst component (A) is a complex of an organomagnesium compoundrepresented by the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2

wherein

M, R¹, R², X¹, X², α, p, q, r and s are the same as defined above,

with an electron donor represented by D, and the organomagnesiumcompound includes dihydrocarbyl magnesium R₂ Mg wherein R is ahydrocarbon group and complexes of dihydrocarbyl magnesium with otherorganometal compounds.

In this formula, R¹ is a hydrocarbon group having 1 to 20 carbon atoms.Exemplary hydrocarbon groups include alkyl groups such as methyl, ethyl,propyl, butyl, amyl, hexyl and decyl groups; cycloalkyl groups such ascyclohexyl group; aryl groups such as phenyl group; and aralkyl groupssuch as benzyl group. Of these groups, alkyl groups are preferred. R² isa secondary or tertiary alkyl group having 3 to 20 carbon atoms, andlower alkyl groups are preferred. Exemplary alkyl groups includeisopropyl, sec-butyl, tert-butyl, sec-amyl, tert-amyl, sec-hexyl andsec-octyl groups. In this invention, these secondary or tertiary alkylgroups are very important, and the advantageous effects of thisinvention can be brought about only by using the organomagnesiumcomponent (i) having such alkyl groups.

M is a metal of the 1st to 3rd groups of the Periodic Table. Examplarymetals represented by M include lithium, sodium, potassium, beryllium,calcium, strontium, barium, zinc, boron and aluminum. Of these metals,lithium, beryllium, boron, aluminum and zinc are preferred due to theirease in making hydrocarbon-soluble organomagnesium complexes. A morepreferred metal is aluminum. The atomic ratio of M to Mg, i.e., α may bewidely varied including zero but it is preferred to employhydrocarbon-soluble organomagnesium complexes in which α is 0 to 1.5. Itis more preferred to employ the organomagnesium compound in which α is 0to 1.

In general, organomagnesium compounds are insoluble in an inerthydrocarbon medium but those with α>0 are soluble in an inerthydrocarbon medium. In this invention it is essential that theorganomagnesium compounds are soluble in an inert hydrocarbon medium.Also organomagnesium compounds with α=0 such as (sec--C₄ H₉)₂ Mg,(tert--C₄ H₉)₂ Mg, (iso--C₃ H₇)Mg(n--C₄ H₉) and (sec--C₄ H₉)Mg(n--C₄ H₉)which are soluble in an inert hydrocarbon can be used in this inventionwith good results.

X¹ and X² in the organomagnesium component (i) each independently is ahydrogen atom or an organic electronegative group containing O, N or S.Exemplary organic electronegative groups include OR⁴, OSiR⁵ R⁶ R⁷, NR⁸R⁹, SR¹⁰ and ##STR1## ps wherein R⁴, R¹⁰, R¹¹ and R¹³ each independentlyis a hydrocarbon group having 1 to 20 carbon atoms and R⁵, R⁶, R⁷, R⁸,R⁹ and R¹² each independently is a hydrogen atom or a hydrcarbon grouphaving 1 to 20 carbon atoms. Exemplary hydrocarbon groups include alkylgroups such as methyl, ethyl, propyl, butyl, amyl, hexyl and decylgroups; cycloalkyl groups such as cyclohexyl group; aryl groups such asphenyl group; and aralkyl groups such as benzyl group. Of these organicelectronegative groups, OR⁴ and OSiR⁵ R⁶ R⁷ are preferred.

α, p, 1, r and s each independently is 0 or a number greater than 0 andthe relationship of p+q+r+s=mα+2 wherein m is the valence of M issatisfied. This relationship shows stoichiometry between the valence ofM plus Mg and the substitutents. The range of 0≦(r+s)/(α+1) <2designates that a total number of X¹ and X² per total number of M and Mgis 0 to 2. It is preferred to employ the organomagnesium compoundscontaining X¹ and X². A preferred range is 0<(r+s)/(α+1)<1.5, especially0.1≦(r+s)/(α+1)≦1.3 in obtaining a high catalyst efficiency at hightemperatures.

The organomagnesium compounds can be prepared by reacting a compound ofR¹ MgQ or R₂ ¹ Mg wherein R¹ is the same as defined above and Q is ahalogen atom, with an organometal compound of MR_(m) ², Mr_(a) ² X_(b) ¹X_(c) ² or MQ_(a) X_(b) ¹ X_(c) ² wherein M, R², X¹, X², Q and m are thesame as defined above and a+b+c=m, in an inert hydrocarbon medium suchas hexane, heptane, octane, cyclohexane, benzene and toluene at atemperature of about 0° C. to about 150° C., and, if necessary or ifdesired, further reacting the resulting reaction product with analcohol, siloxane, amine, imine, thiol or a dithio compound.Furthermore, the organomagnesium compound can be prepared by reacting acompound of MgX₂ ¹ or R¹ MgX¹ with a compound of MR_(m) ² or MR_(m-1) ²H or by reacting a compound of R¹ MgX¹ or R₂ ¹ Mg with a compound ofR_(n) ² MX_(m-n) ² or X_(a) ¹ MX_(m-a) ² wherein M, R¹, R², X¹, X² and mare the same as defined above and a and n each independently is a numberof 0 to m.

The electron donor represented by D is an electron donative organiccompound containing O, N, S or P. Examplary electron donors used in thisinvention include ethers such as diethyl ether, dibutyl ether, diisoamylether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether,glycerol trimethyl ether, vinyl methyl ether, tetrahydrofuran, dioxane,crown ether and propylene oxide; siloxanes such as hexamethyldisoloxane,sym-dihydrotetramethyldisiloxane, pentamethyltrihydrotrisiloxane,methylhydrocyclotetrasiloxane, methylhydropolysiloxane,dimethylpolysiloxane and phenylhydropolysiloxane; tertiary amines suchas triethylamine, tributylamine, tetramethylethylenediamine,bis(diethylamino)methane, and diazabicyclooctane; nitriles such asacetonitrile, propionitrile, acrylonitrile, benzylnitrile andbenzonitrile; amides such as dimethylformamide and hexamethylphosphorictriamide; pyridines such as pyridine and methylpyridine; thioethers suchas diethyl sulfide, ethylpropyl sulfide, dipropyl sulfide and ethylenesulfide; sulfoxides such as dimethyl sulfoxide, diethyl sulfoxide anddibutyl sulfoxide; phosphines such as triethylphosphine andtriphenylphosphine and esters such as ethyl benzoate and ethyl acetate.Of these compounds, ethers, siloxanes and amines are preferred. Morepreferred are siloxanes.

The suffix t designates the amount of electron donor coordinated with Mor Mg and represents zero or a number greater than zero. In order toobtain a high catalyst efficiency at high temperatures, it is importantthat the electron donor is coordinated with M or Mg. A preferred tranges from about 0.05 to about 10, and a more preferred t ranges fromabout 0.2 to about 2.

The complex of the organomagnesium compound with the electron donor canbe easily prepared by contacting the organomagnesium compound with theelectron donor at a temperature of about -20° C. to about 100° C. insuch an inert hydrocarbon medium as employed in the preparation of theorganomagnesium compound.

In the compound (ii) of formula R_(a) ³ CY₄₋₁, R³ is a hydrogen atom, ahydrocarbon group having 1 to 10 carbon atoms such as an alkyl groupincluding methyl, ethyl, propyl, butyl and amyl groups, a halogenatedalkyl group such as trichloromethyl group or an aryl group such asphenyl group. Y is a chlorine, bromine, iodine or fluorine atom. Ofthese halogen atoms, a chlorine atom is preferred. Exemplary compounds(ii) include carbon tetrahalides, carbon monohydrohalides and carbonmonohydrocarbylhalides such as carbon tetrachloride, chloroform,1,1,1-trichloroethane, 1,1,1-trichloropropane, phenyltrichloromethaneand hexachloroethane.

The compounds (iii) of titanium and the compounds (iii) of vanadiumwhich can be employed include halides, oxyhalides, alkoxyhalides,alkoxides and oxyalkoxides of titanium or vanadium such as titaniumtetrachloride, titanium tetrabromide, titanium tetraiodide,ethoxytitanium trichloride, propoxytitanium trichloride, butoxytitaniumtrichloride, dipropoxytitanium dichloride, dibutoxytitanium dichloride,tripropoxytitanium monochloride, tributoxytitanium monochloride,tetrapropoxytitanium, tetrabutoxytitanium, vanadium tetrachloride,vanadyl trichloride, monobutoxyvanadyl dichloride, dibutoxyvanadylmonochloride, tributoxyvanadyl and, ethoxytrichlorovanadium and anymixture thereof. It is preferred to employ compounds of titanium andcompounds of vanadium which have at least one halogen atom such aschlorine atom.

The reaction of the hydrocarbon-soluble organomagnesium component (i),the compound (ii) and the compound (iii) can be conducted in an inertreaction medium or solvent. Exemplary inert reaction solvents employedin this invention include aliphatic hydrocarbons such as hexane, heptaneand octane; aromatic hydrocarbons such as benzene and toluene; alicyclichydrocarbons such as cyclohexane and cyclomethylhexane; and any mixturesthereof. It is preferred from the viewpoint of the catalyst performancesthat aliphatic hydrocarbons are employed. With the order of the reactionof these components (i), (ii) and (iii), previous contact of thecomponent (i) with the compound (iii) should be avoided in order for thecatalyst to exhibit its high activity. More specifically, the surprisingeffect of this invention can be accomplished by firstly reacting thecomponent (i) with the compound (ii) to form a solid product andsecondly contacting the compound (iii) with the surface of the solidproduct effectively.

The reaction between the component (i) and the compound (ii) may becarried out by adding these two components into a reaction zone at thesame time or by firstly charging one of them into the reaction zone andsecondly adding the other into the reaction zone. The reactiontemperature was not particularly limited and typically ranges from about-50° C. to about 150° C. A preferred reaction temperature ranges fromabout 0° C. to about 100° C. from the viewpoint of the progress ofreaction. The mol ratio of the compound (ii) to the component (i) whichcan be employed in this invention is not particularly limited andtypically ranges from about 0.01 to about 100. A preferred mol ratio ofthe halide (ii) to the component (i) ranges from about 0.1 to about 20.The solid product obtained by the reaction between the component (i) andthe compound (ii) may be usually separated by filtration or washed bydecantation and then supplied to the contact with the compound (iii). Inorder to simplify the reaction procedure, it is preferred that thecompound (iii) is added to the reaction solution obtained aftercompletion of the reaction between the component (i) and the compound(ii), and further the contact with the compound (iii) is continued.

In order to impart a high catalyst activity at high temperatures to thecatalyst, it is essential to control the amount of the compound (iii)employed and the concentration of the compound (iii) in the reactionsolution. The atomic ratio of Mg/(Ti+V) which is used in this inventionranges from about 3 to about 500, and a preferred atomic ratio ofMg/(Ti+V) ranges from about 5 to about 200. A more preferred atomicratio of Mg/(Ti+V) ranges from about 10 to about 100. The concentrationof Ti plus V in the reaction solution used in this invention is at most2 mols per liter of the inert reaction solvent. A preferredconcentration of Ti plus V in the reaction solution ranges from about0.01 to about 100 mmols per liter of the inert reaction solvent. Thetemperature for contacting the solid product formed by the reactionbetween the component (i) and the compound (ii) with the compound (iii)is not particularly limited and typically ranges from about -50° C. toabout 150° C., preferably from about 0° C. to about 95° C.

The component (A) of this invention becomes an excellent catalyst forpolymerizing an olefin in combination of an organometal component (B).

Exemplary organometal components (B) which can be used in this inventionare organoaluminum compound including trialkyaluminums such as Al(C₂H₅)₃, Al(C₃ H₇)₃, Al(C₄ H₉)₃, Al(C₅ H₁₁)₃, Al(C₆ H₁₃)₃, Al(C₈ H₁₇)₃ andAl(C₁₀ H₂₁)₃, alkylaluminum halides such as Al(C₂ H₅)₂ Cl, Al(C₂ H₅)Cl₂,Al(i--C₄ H₉)₂ Cl and Al(C₂ H₅)₂ Br, alkylaluminum alkoxides such asAl(C₂ H₅)₂ (OC₂ H₅) and Al(i--C₄ H₉)₂ (OC₄ H₉), alkylaluminum siloxidessuch as Al(C₂ H₅)₂ (OSiH.CH₃.C₂ H₅) and Al(i--C₄ H₉)[OSi(CH₃)₂ (i--C₄H₉)]₂, reaction products of a trialkylaluminum and a conjugated dienesuch as aluminum isoprenyl and aluminum myrcenyl; organoboron compoundssuch as trialkylborons such as B(C₂ H₅)₃, B(C₃ H₇)₃, B(C₄ H₉)₃, B(C₆H₁₃)₃ and B(C₈ H₁₇)₃, triarylborons such as B(C₆ H₅)₃, alkylboronalkoxides such as B(C₅ H₁₁)₂ (OC₄ H₉) and alkylboron halides such asB(C₇ H₁₅)₂ Cl; organozinc compounds such as dialkylzincs including Zn(C₂H₅)₂, Zn(C₄ H₉)₂, Zn(C₆ H₁₃)₂, Zn(C₈ ₁₇)₂ and Zn(C₂ H₅)(n--C₃ H₇),diarylzincs such as Zn(C₆ H₅)₂ and alkylzinc alkoxides such as Zn(C₃H₇)(OC₄ H₉); organomagnesium compounds of the formula,

    M.sub.α MgR.sub.p.sup.14 R.sub.q.sup.15 X.sub.r.sup.1 X.sub.s.sup.2

wherein

R¹⁴ and R¹⁵ each independently is a hydrocarbon group having 1 to 20carbon atoms,

M, X¹, X², a, p, q, r and s are the same as defined above,

which include the same organomagnesium compounds as described above; andany mixtures thereof. Of these organometal compounds, organoaluminumcompounds are preferred, and trialkylaluminum are more preferred.

The component (A) and the organometal component (B) may be added underthe polymerization conditions to the polymerization system or may becombined prior to the polymerization.

The mol ratio of the organometal component (B) to (Ti+V) in thecomponent (A) typically ranges from about 3 to about 1,000 andpreferably ranges from about 5 to about 500.

The catalyst of this invention is suitable for the polymerization ofethylene and may also be employed for the copolymerization of ethylenewith another α-olefin having 3 to 20 carbon atoms such as propylene,butene-1, isobutene, hexene-1, 4-methylpentene-1, octene-1 and or with apolyene such as butadiene and isoprene. In the copolymerization it ispreferred to employ the mol ratio of the α-olefin to be copolymerized toethylene of at most 5. According to this invention it is possible toproduce polyethylene having a density of about 0.975 to about 0.910 bythe homo- or co-polymerization of ethylene.

In this invention, polymerization is conducted at a temperature rangingfrom about 120° C. to about 320° C., preferably from about 150° C. toabout 300° C. by the solution polymerization method. As thepolymerization medium or solvent there can be employed aliphatichydrocarbons such as hexane, heptane or octane; aromatic hydrocarbonsuch as benzene, toluene or xylene; and alicyclic hydrocarbons such ascyclohexane or methylcyclohexane. The catalyst is introduced into areactor together with the polymerization solvent and ethylene is addedat a pressure of ethylene of from about 0.1 to about 40 MPa, preferablyfrom about 1 to about 25 MPa in an inert atmosphere and polymerized.Also it is possible to employ such a means as a stirrer for providingbetter contact between ethylene and the catalyst in the polymerization.

In this invention there may be employed single stage polymerizationhaving one polymerization zone or multistage polymerization having aplurality of polymerization zones. The catalyst of this invention canprovide polyethylene having a narrow molecular weight distribution inthe single stage polymerization and polyethylene having a broadmolecular weight distribution in the multistage polymerization.

In order to control the molecular weight of the polymer, the temperatureof the reactor may be varied or it is also possible to add hydrogen oran organic compound which can easily cause chain transfer. Furthermore,the process of this invention may be combined with a method of using atitanate as a third component for controlling the density of the polymerformed.

The present invention will now be illustrated in greater detail withreference to several Examples, but they are given for illustrativepurposes only and are not to be construed as limiting the invention.

In these examples MI designates a melt index of a polymer which ismeasured at 190° C. under a load of 2.16 Kg in accordance with ASTMD-1238. FR designates a flow ratio represented by MI₂₁.6 /MI₂.16 whereinMI₂₁.6 is a melt index of the polymer measured at 190° C. under a loadof 21.6 Kg and MI₂.16 is the melt index measured at 190° C. under a loadof 2.16 Kg and is one of the criteria for the molecular weightdistribution. A lower FR shows a narrower molecular weight distribution.The term "catalyst efficiency" shows the amount of polymer formed inkilogram per gram of Ti plus V.

EXAMPLE 1

(I) Synthesis of Component (A)

The oxygen and moisture present inside a 250 ml flask equipped with adropping funnel and a water-cooled reflux condenser were purged withnitrogen, and to the flask were charged 20 ml of a heptane solutioncontaining chloroform in an amount of 0.1 mol per liter of heptane and30 ml of heptane in a nitrogen atmosphere and the temperature was raisedto 70° C. Then 20 ml of a heptane solution containing 2.1 ml of Al₀.1Mg(n--C₄ H₉)₁.0 (sec--C₄ H₉)₁.0 (On--C₄ H₉)₀.3 were accurately measured,charged in the dropping funnel and added drop-wise to the flask at 70°C. with stirring over 2 hours, resulting in a white suspension reactionsolution. To the obtained suspension reaction solution were added 20 mlof a heptane solution containing 5.7 mg of titanium tetrachloride at aconcentration of titanium of 0.3 mmol per liter of heptane and thereaction was continued at 70° C. for two hours.

(II) Polymerization of Ethylene

In a 1l autoclave evacuated were charged 5 ml of the component (A) asobtained above and 0.02 mmol of trioctyl aluminum with 0.6l ofdehydrated and deaerated octane, and then 10 mmols of hydrogen wasintroduced into the autoclave. While keeping the temperature of theautoclave at 190° C., ethylene was introduced into the autoclave at apressure of 4.0 MPa and the polymerization was carried out for 20minutes while maintaining the total pressure constant by supplyingadditional ethylene, resulting in 54 g of a polymer. The catalystefficiency was 750 Kg/g Ti, MI was 6.9, FR was 24, the density was 0.967g/cc.

EXAMPLES 2 to 11

Components (A) were prepared by reacting the hydrocarbon-solubleorganomagnesium component (i) with the compound (ii) under the reactionconditions as set forth in Table 1 and subsequently contacting theobtained product with the compound (iii) under the reaction conditionsas set forth in Table 1 in the same manner as described in Example 1.Using 5 ml of these components (A) and organometal compounds (B) as setforth in Table 2 under the reaction conditions as set forth in Table 2,polymerization of ethylene was carried out under the polymerizationconditions as set forth in Table 2 in the same manner as in Example 1.The results are shown in Table 2.

                                      TABLE 1                                     __________________________________________________________________________                                                            [(i) + (ii)] +                                         (i) + (ii)       Concentra-                                                                          (iii)                                                  Reaction         tion or                                                                             Reaction                                               Conditions       tanium                                                                              Conditions            Ex-                              Tem-             Vanadium                                                                            Tem-                  am-                       Compound                                                                             pera-            (mmol                                                                               pera-                 ple                                                                              Organomagnesium Component (i)                                                                        (ii)   ture                                                                             Time                                                                              Compound (iii)                                                                          liter                                                                               ture                                                                             Time               No.                                                                              (mmol)                 (mmol) (°C.)                                                                     (hour)                                                                            (mmol)    solvent)                                                                            (°C.)                                                                     (hour)             __________________________________________________________________________    2  Li.sub.0.1 Mg(n-C.sub.4 H.sub.9).sub.0.6 (sec-C.sub.4 H.sub.9).sub.0.6        (On-C.sub.6 H.sub.13).sub.0.9                                                                        HCCl.sub.3                                                                           70 2   TiCl.sub.3 (Oi-C.sub.3 H.sub.7)                                               +         1.5   90 2                          2.0               20.0          0.100                                                                         VOCl.sub.3                                                                    0.050                                 3  Al.sub.0.4 Mg(n-C.sub.6 H.sub.13).sub.1.3 (i-C.sub.3 H.sub.7).sub.0.5         [OSi(CH.sub.3).sub.3 ].sub.1.4                                                                       CCl.sub.4                                                                            50 2   TiCl.sub.4 +                                                                            2.4   80 3                           2.0              30.0          0.120                                                                         VO(On-C.sub.4 H.sub.9).sub.3                                                  0.120                                 4  Al.sub.0.2 Mg(C.sub.2 H.sub.5).sub.1.4 (sec-C.sub.4 H.sub.9).sub.0.9          (On-C.sub.3 H.sub.7).sub.0.3                                                                         CH.sub.3 CCl.sub.3                                                                   100                                                                              1   TiCl.sub.4                                                                              1.38  20 6                          2.0               15.0          0.138                                 5  ZnMg(C.sub.2 H.sub.5).sub.1.7 (sec-C.sub.5 H.sub.11).sub.1.0 (SC.sub.2        H.sub.5).sub.1.3       C.sub.6 H.sub.5 CCl.sub.3                                                            0  10  TiCl.sub.3 (Oi-C.sub.3 H.sub.7)                                                         0.051 70 1                          2.0               50.0          0.0051                                6  BMg(n-C.sub.4 H.sub.9).sub.3.3 (sec-C.sub.6 H.sub.13).sub.1.2 [N(CH.sub       .3).sub.2 ].sub.0.5    n-C.sub.8 H.sub.17 CCl.sub.3                                                         -10                                                                              15  TiCl.sub.2 (On-C.sub.4 H.sub.9).su                                            b.2       1.65  100                                                                              1                          2.0               80.0          0.165                                 7  Mg(n-C.sub.4 H.sub.9)(sec-C.sub.4 H.sub.9)                                                           Cl.sub.3 CCCl.sub.3                                                                  60 3   VOCl.sub.3                                                                              1.85  50 4                          2.0                0.3          0.185                                 8  Al.sub.0.9 Mg(n-C.sub.3 H.sub.7)(t-C.sub.5 H.sub.11).sub.1.2 (On-C.sub.       4 H.sub.9).sub.1.5     C.sub.2 H.sub.5 CCl.sub.3                                                            20 6   TiCl.sub.3 (Oi-C.sub.3 H.sub.7)                                                         0.07  80 1                          2.0                1.0          0.002                                                                         VOCl.sub.3                                                                    0.005                                 9  Al.sub.0.17 Mg(C.sub.2 H.sub.5).sub.0.51 (n-C.sub.4 H.sub.9)(sec-C.sub.       4 H.sub.9) .           HCCl.sub.3                                                                           50 6   TiCl.sub.4 +                                                                            10.0  65 1                     [O(n-C.sub.4 H.sub.9).sub.2 ].sub.0.30      2.0                                                       6.6          0.042                                                                         VO(On-C.sub.4 H.sub.9).sub.3                                                  0.060                                 10 Al.sub.0.4 Mg(n-C.sub.6 H.sub.13).sub.2.2 (i-C.sub.3 H.sub.7){O[Si(CH.s       ub.3).sub.2 H].sub.2 }.sub.1.4                                                                       HCCl.sub.3                                                                           80 3   TiCl.sub.4 +                                                                            1.2   70 2                          2.0                2.2          0.070                                                                         VOCl.sub.2 (On-C.sub.4 H.sub.9)                                               0.050                                 11 Al.sub.0.3 Mg(n-C.sub.4 H.sub.9).sub.1.8 (sec-C.sub.4 H.sub.9).sub.0.9        (On-C.sub.4 H.sub.9).sub.0.2 .                                                                       CCl.sub.4                                                                            80 3   TiCl.sub.4                                                                              1.6   70 2                     [N(CH.sub.2).sub.3 N].sub.0.2       2.0                                                               4.0          0.160                                 __________________________________________________________________________

                                      TABLE 2                                     __________________________________________________________________________                        Polymerization Conditions                                                                      Result of Polymerization                                     Polymerization                                                                        Ethylene Catalyst                                 Example                                                                            Organometal Compound (B)                                                                     Temperature                                                                           Pressure                                                                           H.sub.2                                                                           Efficiency                               No.  (mmol)         (°C.)                                                                          (MPa)                                                                              (mmol)                                                                            [Kg/g(Ti + V)]                                                                        MI FR                            __________________________________________________________________________    2    Al(C.sub.2 H.sub.5).sub.3                                                                 0.05                                                                             180     3.0  15  516     5.4                                                                              25                            3    Al(n-C.sub.8 H.sub.17).sub.3                                                              0.12                                                                             180     3.0  15  508     1.2                                                                              28                            4    Al(i-C.sub.4 H.sub.9).sub.3                                                               0.32                                                                             180     3.0  15  586     3.5                                                                              22                            5    Al(C.sub.2 H.sub.5).sub.2.7 Cl.sub.0.3                                                    5.21                                                                             180     3.0  15  416     12.5                                                                             26                            6    Al(n-C.sub.4 H.sub.9).sub.2.4 (OC.sub.2 H.sub.5).sub.0.6                                  1.29                                                                             180     3.0  15  432     1.6                                                                              35                            7    Aluminum isoprenyl                                                                        0.87                                                                             180     3.0  15  395     7.3                                                                              30                            8    Al(C.sub.2 H.sub.5).sub.3                                                                 0.03                                                                             180     3.0  10  498     9.7                                                                              28                            9    Al(C.sub.2 H.sub.5).sub.3                                                                 0.09                                                                             200     3.0  10  532     6.5                                                                              22                            10   Al(C.sub.2 H.sub.5).sub.3                                                                 0.24                                                                             200     3.0  10  505     1.2                                                                              24                            11   Al(n-C.sub.6 H.sub.13).sub.3                                                              0.36                                                                             200     3.0  10  574     8.5                                                                              19                            __________________________________________________________________________

EXAMPLES 12 to 18

(I) Synthesis of Component (A)

2 mmols of Al₀.2 Mg(C₂ H₅)₀.6 (n--C₄ H₉)₂ were mixed with a siloxanecompound as set forth in Table 3 at 30° C. to form a hydrocarbon-solubleorganomagnesium component (i). The component (A) was prepared in thesame manner as in Example 1 except that the obtained component (i), thecompound (ii), the compound (iii) and the reaction conditions as setforth in Table 3 were used.

(II) Polymerization of Ethylene

Using 2.5 ml of the obtained component (A), the organometal component(B) and the polymerization conditions as set forth in Table 4,polymerization of ethylene was conducted in the same manner as inExample 1. The results are shown in Table 4.

                                      TABLE 3                                     __________________________________________________________________________                                                         [(i) + (ii)] +                                                                (iii)                                                                 Concentration                                                                         Reaction                                                              of Titanium                                                                           Conditions                    Electron Donor         Temper-          plus Vanadium                                                                         Temper-                  Example                                                                            Siloxane Compound                                                                            Compound (ii)                                                                         ature                                                                              Time                                                                              Compound (iii)                                                                        (mmol per liter                                                                       ature                                                                              Time                No.  (mmol)         (mmol)  (°C.)                                                                       (hour)                                                                            (mmol)  of solvent)                                                                           (°C.)                                                                       (hour)              __________________________________________________________________________    12   Dimethylpolysiloxane                                                                         CHCl.sub.3                                                                            120  2   TiCl.sub.4 + VCl.sub.4                                                                 1.92   90   3                        (viscosity: 20 centistokes)                                                                  1.9              0.128  0.064                                  2.0                                                                      13   Methylhydropolysiloxane                                                                      CHCl.sub.3                                                                            80   2     TiCl.sub.4                                                                          0.4     70   1                        (viscosity: 20 centistokes)                                                                  4.0                0.040                                       1.0                                                                      14   Dihydrotetramethyldisiloxane                                                                 CCl.sub.4                                                                             90   10  TiCl.sub.4 + VOCl.sub.3                                                               0.7     60   3                        4.5            3.6              0.035  0.035                             15   Dihydrotetramethyldisiloxane                                                                 CCl.sub.4                                                                             "    "   TiCl.sub.4 + VOCl.sub.3                                                               "       "    "                        4.5            3.6              0.035  0.035                             16   Dihydrotetramethyldisiloxane                                                                 CCl.sub.4                                                                             "    "   TiCl.sub.4 + VOCl.sub.                                                                "       "    "                        4.5            3.6              0.035  0.035                             17   Dihydrotetramethyldisiloxane                                                                 CCl.sub.4                                                                             "    "   TiCl.sub.4 + VOCl.sub.3                                                               "       "    "                        4.5            3.6              0.035  0.035                             18   Dihydrotetramethyldisiloxane                                                                 CCl.sub.4                                                                             "    "   TiCl.sub.4 + VOCl.sub.3                                                               "       "    "                        4.5            3.6              0.035  0.035                             __________________________________________________________________________

                                      TABLE 4                                     __________________________________________________________________________                           Polymerization Conditions                                                                      Result of Polymerization                                     Polymerization                                                                        Ethylene Catalyst                              Example                                                                            Organometal Compound (B)                                                                        Temperature                                                                           Pressure                                                                           H.sub.2                                                                           Efficiency                            No.  (mmol)            (°C.)                                                                          (MPa)                                                                              (mmol)                                                                            Kg/g (Ti + V)                                                                         MI FR                         __________________________________________________________________________    12   Al(C.sub.2 H.sub.5).sub.3                                                                    0.061                                                                            190     2.5  30  703     6.4                                                                              22                         13   Al(C.sub.2 H.sub.5).sub.3                                                                    0.120                                                                            160     3.0  15  502     2.5                                                                              26                         14   Al(n-C.sub.4 H.sub.9).sub.3                                                                  0.225                                                                            180     3.0  20  511     3.6                                                                              28                         15   B(C.sub.2 H.sub.5).sub.2.7 Cl.sub.0.3                                                        0.359                                                                            160     3.0  30  385     10.2                                                                             23                         16   Al.sub.0.8 Mg(C.sub.2 H.sub.5).sub.3.4 (sec-C.sub.5 H.sub.11)                                0.135                                                                            160     3.0  30  406     8.6                                                                              24                         17   Zn(n-C.sub.6 H.sub.13).sub.2                                                                 0.204                                                                            160     3.0  40  298     5.4                                                                              22                         18   Li.sub.0.2 Mg(n-C.sub.4 H.sub.9).sub.1.2 (sec-C.sub.4 H.sub.9)                               0.246                                                                            160     3.0  35  396     6.2                                                                              32                         __________________________________________________________________________

EXAMPLE 19

In the same manner as in Example 1, 1.0 mol of ethylene were polymerizedat 140° C. at a pressure of ethylene of 4.0 MPa in the presence of 3mmols of hydrogen by using 2.0 ml of the same component (A) as inExample 1 and 0.05 mmol of trioctyl aluminum. Then, after 80 mmols ofhydrogen were introduced into the autoclave and its inner temperaturewas raised to 200° C., 1.2 mols of ethylene were further polymerized asa pressure of ethylene of 2.0 MPa, resulting in a polymer having a MI of2.6 and a FR of 86.

EXAMPLE 20 to 24

A component (A) was prepared in the same manner as in Example 1 exceptthat 2.0 mmols of Al₀.05 Mg(C₂ H₅)₁.05 (sec--C₄ H₉)[O(n--C₄ H₉)₂ ]₀.3,3.5 mmols of HCCl₃, 0.15 mmol to TiCl₄ and 0.05 mmol of VOCl₃ at aconcentration of titanium plus vanadium of 2.0 mmols per liter of thereaction solvent were employed.

In a 1l autoclave evacuated were charged 4 ml of the obtained component(A) and 0.16 mmol of Al(i--C₄ H₉)₃ with 0.6l of dehydrated and deaeratedmethylcylohexane. After 10 mmols of hydrogen and an olefin as set forthin Table 5 were introduced into the autoclave, its inner temperature wasraised to the one as set forth in Table 5 and then ethylene was added upto a pressure of 3.0 MPa. Until 1.5 mmols of ethylene was polymerized,copolymerization of ethylene was continued while maintaining the totalpressure constant by supplying additional ethylene. The results areshown in Table 5.

                  TABLE 5                                                         ______________________________________                                        Ex-                   Polymer- Products                                       am-                   ization            Den-                                 ple  α-Olefin   Tempera-           sity                                 No.  (mmol)           ture (°C.)                                                                      MI   FR   (g/cc)                               ______________________________________                                        20   4-Methylpentene-1                                                                           100    180    2.6  28   0.946                              21   Octene-1      200    180    8.6  22   0.943                              22   Butene-1      500    160    12.5 19   0.932                              23   4,4-Dimethyl-                                                                 pentene-1     400    160    3.6  25   0.930                              24   Hexene-1      1000   160    12.5 22   0.924                              ______________________________________                                    

What is claimed is:
 1. A process for polymerizing an α-olefin comprisingcontacting the olefin in liquid phase at a temperature of about 120° to320° C. with a catalyst comprising a component (A) and an organometalcomponent (B), the compenent (A) being produced by reacting ahydrocarbon-soluble organomagnesium component (i) of the formula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein α, p, q, r, s and t each independently is 0 or a number greaterthan 0, [< (r+s)/(α+1)<2, ]0<(r+s)/(α+1)<1.5, m is the valence of M, Mis a metal of the 1st to 3rd groups of the Periodic Table, R¹ is ahydrocarbon group having 1 to 20 carbon atoms, R² is a secondary ortertiary alkyl group having 3 to 20 carbon atoms, X¹ and X² eachindependently is a hydrogen atom or an organic electronegative groupcontaining O, N or S, D is an electron donor,with a compound (ii) of theformula,

    R.sub.a.sup.3 CY.sub.4-a

wherein R³ is a hydrogen atom or a hydrocarbon group having 1 to 10carbon atoms, Y is a halogen atom, a is 0 or 1,and contacting theproduct of (i)+(ii) with (iii) a compound of tetravalent titanium and/ora compound of pentavalent or tetravalent vanadium at a concentration oftitanium plus vanadium of at most about 2 mols per liter of an inertreaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 toabout
 500. 2. A process of claim 1, wherein M in the organomagnesiumcomponent (i) of the component (A) is lithium, berylium, boron, aluminumor zinc metal.
 3. A process of claim 2, wherein M in the organomagnesiumcomponent (i) of the component (A) is aluminum metal.
 4. A process ofclaim 1, wherein α in the organomagnesium component (i) is 0≦α≦1.
 5. Aprocess of claim 4, wherein α in the organomagnesium component (i) is0<α≦0.5.
 6. A process of claim 1, wherein X¹ and X² in theorganomagnesium component (i) each independently is OR⁴, OSiR⁵ R⁶ R⁷,NR⁸ R⁹, SR¹⁰ or ##STR2## wherein R⁴, R¹⁰, R¹¹ and R¹³ each independentlyis a hydrocarbon group having 1 to 20 carbon atoms and R⁵, R⁶, R⁷, R⁸,R⁹ and R¹² each independently is a hydrogen atom or a hydrocarbon grouphaving 1 to 20 carbon atoms.
 7. A process of claim 6, wherein X¹ and X²in the organomagnesium component (i) each independently is OR⁴.
 8. Aprocess of claim 6, wherein X¹ and X² in the organomagnesium component(i) each independently is OSiR⁵ R⁶ R⁷.
 9. A process of claim 1, whereinthe polymerization temperature is about 180° C.
 10. A process of claim1, wherein the amount of X¹ and X² in the organomagnesium component (i)is 0.1≦(r+s)/(α+1)≦1.3.
 11. A process of claim 1, wherein the electrondonor represented by D is an electron donative organic compoundcontaining O, N, S or P.
 12. A process of claim 11, wherein the electrondonative organic compound is an ether, a siloxane, a tertiary amine, anitrile, an amide, a pyridine, a thioether, a sulfoxide or a phosphine.13. A process of claim 12, wherein the electron donative organiccompound is an ether.
 14. A process of claim 12, wherein the electrondonative organic compound is a siloxane.
 15. A process of claim 12,wherein the electron donative organic compound is an amine.
 16. Aprocess of claim 1, wherein t in the organomagnesium component (i) isabout 0.05 to about
 10. 17. A process of claim 1, wherein t in theorganomagnesium component (i) is about 0.2 to about
 2. 18. A process ofclaim 1, wherein the compound (ii) is a carbon tetrahalide, a carbonmonohydrohalide or a carbon monoalkylhalide.
 19. A process of claim 18,wherein the carbon tetrahalide is carbon tetrachloride.
 20. A process ofclaim 18, wherein the carbon monohydrohalide is chloroform.
 21. Aprocess of claim 1, wherein (iii) the compound of titanium and/or thecompound of vanadium contains at least one chlorine atom.
 22. A processof claim 1, wherein the reaction between the component (i) and thecompound (ii) is conducted at a temperature of about -50° to about 150°C.
 23. A process of claim 1, wherein the mol ratio of the compound (ii)to the component (i) is about 0.01 to about
 100. 24. A process of claim1, wherein the mol ratio of the compound (ii) to the component (i) isabout 0.1 to about
 20. 25. A process of claim 1, wherein the contact ofthe reaction product of (i)+(ii) with (iii) the compound of titaniumand/or the compound of vanadium is conducted at a temperature of about-50° to about 150° C.
 26. A process of claim 25, wherein the contact ofthe reaction product of (i)+(ii) with (iii) the compound of titaniumand/or the compound of vanadium is conducted at a temperature of about0° to about 95° C.
 27. A process of claim 1, wherein the atomic ratio ofMg/(Ti+V) in the component (A) is about 5 to about
 200. 28. A process ofclaim 27, wherein the atomic ratio of Mg/(Ti+V) in the component (A) isabout 10 to about
 100. 29. A process of claim 1, wherein the reactionproduct of the component (i) and the compound (ii) is contacted with(iii) the compound of titanium and/or the compound of vanadium at aconcentration of titanium plus vanadium of about 0.01 mmol to about 100mmols per liter of the inert reaction solvent.
 30. A process of claim 1,wherein the organometal component (B) is an organoaluminum compound, anorganoboron compound, an organozinc compound or an organomagnesiumcompound.
 31. A process of claim 30, wherein the organometal component(B) is an organoaluminum compound.
 32. A process of claim 31, whereinthe organoaluminum compound is a trialkylaluminum, an alkylaluminumhalide, an alkylaluminum alkoxide, an alkylaluminum siloxide and areaction product of a trialkylaluminum and a conjugated diene.
 33. Aprocess of claim 1, wherein the mol ratio of the organometal compound(B) to (Ti+V) in the component (A) is about 3 to about
 1000. 34. Aprocess of claim 1, wherein the α-olefin is ethylene.
 35. A process ofclaim 34, wherein the polymerization of ethylene is carried out at apartial pressure of ethylene of about 1 to about 25 MPa at apolymerization temperature of about 150° to about 300° C.
 36. A processof claim 1, wherein copolymerization of ethylene with an α-olefin otherthan ethylene or a polyene.
 37. A process of claim 36, wherein theα-olefin other than ethylene is a C₃₋₂₀ α-olefin.
 38. A process of claim36, wherein the polyene is butadiene or isoprene.
 39. A process of claim36, wherein the mol ratio of the α-olefin or polyene to ethylene is atmost
 5. 40. A process of claim 1, wherein the polymerization of anα-olefin is conducted in a plurality of polymerization zones.
 41. Acatalyst useful for polymerizing an α-olefin comprising a component (A)and an organometal component (B), the component (A) being produced byreacting a hydrocarbon-soluble organomagnesium component (i) of theformula,

    M.sub.α MgR.sub.p.sup.1 R.sub.q.sup.2 X.sub.r.sup.1 X.sub.s.sup.2 D.sub.t

wherein α, p, q, r, s and t each independently is 0 or a number greaterthan 0, p+q+r+s=mα=2, 0≦(r+s)/(α+1)<2,]0<(r+s)/(α+1)<1.5, m is thevalence of M, M is a metal of the 1st to 3rd groups of the PeriodicTable, R¹ is a hydrocarbon group having 1 to 20 carbon atoms, R² is asecondary or tertiary alkyl group having 3 to 20 carbon atoms, X¹ and X²each independently is a hydrogen atom or an organic electronegativegroup containing O, N or S, D is an electron donor,with a compound (ii)of the formula,

    R.sub.a.sup.3 CY.sub.4-1

wherein R³ is a hydrogen atom or a hydrocarbon group having 1 to 10carbon atoms, Y is a halogen atom, a is 0 or 1,and contacting theproduct of (i)+(ii) with (iii) a compound of tetravalent titanium and/ora compound of pentavalent or tetravalent vanadium at a concentration oftitanium plus vanadium of at most about 2 mols per liter of an inertreaction solvent, the atomic ratio of Mg/(Ti+V) in (A) being about 3 toabout 500.